Instability of the perceived world while watching 3D stereoscopic imagery: A likely source of motion sickness symptoms.

Hwang AD, Peli E - Iperception (2014)

Bottom Line:
Numerous studies have reported motion-sickness-like symptoms during stereoscopic viewing, but no causal linkage between specific aspects of the presentation and the induced discomfort has been explicitly proposed.Here, we describe several causes, in which stereoscopic capture, display, and viewing differ from natural viewing resulting in static and, importantly, dynamic distortions that conflict with the expected stability and rigidity of the real world.This analysis provides a basis for suggested changes to display systems that may alleviate the symptoms, and suggestions for future studies to determine the relative contribution of the various effects to the unpleasant symptoms.

ABSTRACTWatching 3D content using a stereoscopic display may cause various discomforting symptoms, including eye strain, blurred vision, double vision, and motion sickness. Numerous studies have reported motion-sickness-like symptoms during stereoscopic viewing, but no causal linkage between specific aspects of the presentation and the induced discomfort has been explicitly proposed. Here, we describe several causes, in which stereoscopic capture, display, and viewing differ from natural viewing resulting in static and, importantly, dynamic distortions that conflict with the expected stability and rigidity of the real world. This analysis provides a basis for suggested changes to display systems that may alleviate the symptoms, and suggestions for future studies to determine the relative contribution of the various effects to the unpleasant symptoms.

Figure 4: Distribution of ADs and VEs when fixating on different objects: fixating (a) on O1, (b) on O5, and (c) on O9, in the sample scene. Although the absolute AD of objects changes for different fixation conditions, the (relative) AD differences among objects are the same regardless of fixation changes. (Absolute ADs are dependent on the fixated object's location.) Fixated objects are circled in the legends. The vertical axis represents AD in degrees, with negative values representing uncrossed disparities. Depth increases as disparity decreases monotonically. Note that positive/negative disparity and crossed/uncrossed disparity are often mixed in use. While positive disparity means a closer object here (and in graphics/image processing literature), crossed disparity means a closer objects in optometric/clinical literature. Zero disparity, however, does not generally imply that an object is at the same egocentric distance as fixation, unless the object and fixation are the same angle from the midline.

Mentions:
To examine the stability of the AD structure across eye movements, VEs and ADs of objects in the sample scene were computed while assuming that the viewer's head position remains in the center of the world (the origin of our scene) as the eyes fixate different objects in the grid (Figure 4). Note that linear perspective projection was applied to the spatial configuration, so the plots show the VE and AD of each object as seen by the viewer. Thus, we have changed the horizontal axes from the meters of Figure 3a to degrees of visual angle in Figure 4.

Figure 4: Distribution of ADs and VEs when fixating on different objects: fixating (a) on O1, (b) on O5, and (c) on O9, in the sample scene. Although the absolute AD of objects changes for different fixation conditions, the (relative) AD differences among objects are the same regardless of fixation changes. (Absolute ADs are dependent on the fixated object's location.) Fixated objects are circled in the legends. The vertical axis represents AD in degrees, with negative values representing uncrossed disparities. Depth increases as disparity decreases monotonically. Note that positive/negative disparity and crossed/uncrossed disparity are often mixed in use. While positive disparity means a closer object here (and in graphics/image processing literature), crossed disparity means a closer objects in optometric/clinical literature. Zero disparity, however, does not generally imply that an object is at the same egocentric distance as fixation, unless the object and fixation are the same angle from the midline.

Mentions:
To examine the stability of the AD structure across eye movements, VEs and ADs of objects in the sample scene were computed while assuming that the viewer's head position remains in the center of the world (the origin of our scene) as the eyes fixate different objects in the grid (Figure 4). Note that linear perspective projection was applied to the spatial configuration, so the plots show the VE and AD of each object as seen by the viewer. Thus, we have changed the horizontal axes from the meters of Figure 3a to degrees of visual angle in Figure 4.

Bottom Line:
Numerous studies have reported motion-sickness-like symptoms during stereoscopic viewing, but no causal linkage between specific aspects of the presentation and the induced discomfort has been explicitly proposed.Here, we describe several causes, in which stereoscopic capture, display, and viewing differ from natural viewing resulting in static and, importantly, dynamic distortions that conflict with the expected stability and rigidity of the real world.This analysis provides a basis for suggested changes to display systems that may alleviate the symptoms, and suggestions for future studies to determine the relative contribution of the various effects to the unpleasant symptoms.

ABSTRACTWatching 3D content using a stereoscopic display may cause various discomforting symptoms, including eye strain, blurred vision, double vision, and motion sickness. Numerous studies have reported motion-sickness-like symptoms during stereoscopic viewing, but no causal linkage between specific aspects of the presentation and the induced discomfort has been explicitly proposed. Here, we describe several causes, in which stereoscopic capture, display, and viewing differ from natural viewing resulting in static and, importantly, dynamic distortions that conflict with the expected stability and rigidity of the real world. This analysis provides a basis for suggested changes to display systems that may alleviate the symptoms, and suggestions for future studies to determine the relative contribution of the various effects to the unpleasant symptoms.